The Children's Investment Fund Management went a long way towards reaching its high-water mark in the first half, but has even longer to go to get to that break-even point.

The London-based activist returned 16.53% in the first half, Morningstar data shows. It's unclear how TCI did during the market doldrums of the third quarter, which cost many hedge funds dearly, but its first-half performance was better than three-times higher than the average stock fund.

Now, the bad news: TCI is still at least 22.27% below its high-water mark.